Study of quantum correlation swapping with relative entropy methods

Study of quantum correlation swapping with relative entropy methods
Xie, Chuanmei; Liu, Yimin; Chen, Jianlan; Zhang, Zhanjun
2015-12-21 00:00:00
To generate long-distance shared quantum correlations (QCs) for information processing in future quantum networks, recently we proposed the concept of QC repeater and its kernel technique named QC swapping. Besides, we extensively studied the QC swapping between two simple QC resources (i.e., a pair of Werner states) with four different methods to quantify QCs (Xie et al. in Quantum Inf Process 14:653–679, 2015). In this paper, we continue to treat the same issue by employing other three different methods associated with relative entropies, i.e., the MPSVW method (Modi et al. in Phys Rev Lett 104:080501, 2010), the Zhang method (
arXiv:1011.4333
[quant-ph]) and the RS method (Rulli and Sarandy in Phys Rev A 84:042109, 2011). We first derive analytic expressions of all QCs which occur during the swapping process and then reveal their properties about monotonicity and threshold. Importantly, we find that a long-distance shared QC can be generated from two short-distance ones via QC swapping indeed. In addition, we simply compare our present results with our previous ones.
http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.pngQuantum Information ProcessingSpringer Journalshttp://www.deepdyve.com/lp/springer-journals/study-of-quantum-correlation-swapping-with-relative-entropy-methods-ylni7pv3OC